Testing equality of variances in the analysis of repeated measurements

The problem of comparing the precisions of two instruments using repeated measurements can be cast as an extension of the Pitman-Morgan problem of testing equality of variances of a bivariate normal distribution. Hawkins (1981) decomposes the hypothesis of equal variances in this model into two subhypotheses for which simple tests exist. For the overall hypothesis he proposes to combine the tests of the subhypotheses using Fisher's method and empirically compares the component tests and their combination with the likelihood ratio test. In this paper an attempt is made to resolve some discrepancies and puzzling conclusions in Hawkins's study and to propose simple modifications.
The new tests are compared to the tests discussed by Hawkins and to each other both in terms of the finite sample power (estimated by Monte Carlo simulation) and theoretically in terms of asymptotic relative efficiencies.     

ML– and semiparametric estimation in logistic models with incomplete covariate data

ML–estimation of regression parameters with incomplete covariate information usually requires a distributional assumption regarding the concerned covariates that implies a source of misspecification. Semiparametric procedures avoid such assumptions at the expense of efficiency. In this paper a simulation study with small sample size is carried out to get an idea of the performance of the ML–estimator under misspecification and to compare it with the semiparametric procedures when the former is based on a correct assumption. The results show that there is only a little gain by correct parametric assumptions, which does not justify the possibly large bias when the assumptions are not met. Additionally, a simple modification of the complete case estimator appears to be nearly semiparametric efficient.     

认证实验室与纯水

强调纯水对认证实验室的重要性，讲屯水制备方法及其相关要求。     

金融制度缺陷:我国农村金融效率低下的根源

本文通过统计数据对我国农村金融资源配置效率的分析表明,我国农村金融资源配置效率相对低下.造成农村金融资源配置效率低下的原因,是现阶段农村金融制度的有效供给不足,导致了金融资源配置无法满足帕累托条件.因此,提高农村金融资源配置效率的关键,在于农村金融制度的创新和有效供给.     

对企业技术创新自我实现的经济学分析

本文从经济学的理论角度分析了企业技术创新自我实现的可能性。分析发现：产品被成熟生产后的产量与资本报酬和资本边际生产率的大小有直接关系。因此，企业发展内部本身就可以通过市场供需调节来实现创新的循环和延续。从这一点上说，国家对于企业技术创新的鼓励政策应该更加依靠市场机制的作用。     

How efficient are national environmental standards? A benefit-cost analysis of the United States experience

This paper summarizes the results of the first systematic, geographically-specific efficiency assessment of the U.S. experience with national environmental standards and with alternative approaches to establishing those standards. This ex-post evaluation assessed the net benefits that resulted from EPA's regulation of conventional air and water pollutants from the pulp and paper industry between 1973 and 1984. The paper compares the benefit-cost efficiencies of the three dominant regulatory approaches: technology, ambient, and benefits. Unlike previous studies, which assessed benefits and costs on a national basis, the study estimates both costs and benefits on a facility-by-facility basis. The analysis shows how the efficiency of national environmental regulations can vary dramatically at local levels. The authors conclude that the technology-based standards for water pollution management failed as an efficient environmental strategy. The costs clearly exceeded the benefits in the aggregate, as well as in the specific in most situations. Benefits exceeded costs at only 11 of the 68 mills investigated. The ambient based standards for air pollution management succeeded as an environmental strategy in the aggregate, but succeeded in the specific for only one-third of the mills (22 of 60 mills). The benefits-based standards for air pollution management also succeeded in the aggregate as well as in the specific for about one-half of the mills. Benefits exceeded costs at 29 of the 60 mills investigated. The results of the study point to two major conclusions. First, a regulatory policy that is based on some measure of environmental results, either ambient-based or benefits-based, will be more efficient than a policy that ignores environmental results. Second, truly efficient policies for reducing environmental risks require pollution mitigation decisions that take into account local conditions. These include not only the changes in local ambient conditions, but also the number of people who will benefit from pollution reduction decisions. This latter conclusion suggests that national environmental standards per se may be inefficient.Dr. Luken is currently Senior Environmental Advisor to the United Nations Industrial Development Organization (UNIDO) in Vienna, Austria. He is on leave from the U.S. EPA where he was Chief of the Economic Analysis and Research Branch of the Office of Policy, Planning and Evaluation (OPPE). Mr. Clark is President of Environmental Economics Associates of Traverse City, Michigan. He was formerly Chief of EPA's Cost and Economic Impact Analysis Branch in OPPE. The views expressed are those of the authors and do not represent the views of the U.S. Environmental Protection Agency.     

中国证券市场价格波动与宏观经济协同性的实证研究

理论上，证券市场常被称为国民经济的“晴雨表”。本文选取工业增加值、广义货币供应量（M2）、消费者景气指数和国房景气指数等宏观经济指标，深入考察了宏观经济与沪深两市股价走势之间的关系。结果表明，在样本期内股价指数波动与宏观经济变量之间不存在协整性特征，中国证券市场与国民经济之间尚未呈现出稳定的长期均衡关系，证券市场并未发挥“国民经济晴雨表”的功能。这也表明，中国证券市场的宏观协调效率还有待于进一步提高。     

Comparing Environmental Policy Instruments in the Presence of Imperfect Compliance – A Case Study

In this paper, we aim to include rule making, implementation, monitoring and enforcement costs into the cost comparison of policy instruments. We use a simple partial equilibrium model and apply it to the textile industry. The model includes discrete abatement functions and costly monitoring and enforcement. The case study uses individual firm data to simulate the differences in abatement costs and compliance decisions between firms. We compare combinations of regulatory instruments (emission taxes, emission standards and technology standards) and enforcement instruments (criminal fines, civil fines and transaction offers). We show that the inclusion of information, monitoring and enforcement costs indeed alters the relative cost efficiency of the different instruments.     

我国西部生态环境建设绩效评价体系研究

“局部改善,整体恶化”是我国西部地区生态环境状况的真实概括。为了治理西部地区的生态环境,党中央于1999年6月确定了西部大开发战略,将能源开发同生态环境治理并举。6年来,中央财政性建设资金投向西部地区4600亿元,转移支付和专项补助5000多亿元。国家计划在10年间退耕还林2．2亿亩,投资3600亿元。由于生态环境建设的绩效是一个漫长的量变累积过程,通过确定我国西部地区生态环境状况四大特征,建立“常态、一般、差”三级评价指标体系,对西部地区生态环境建设的绩效做出客观评价,有利于坚定人们对西部地区生态环境建设的信心。     

基于公平与效率均衡的城乡和谐

已有的对城乡和谐发展问题的研究大多将注意力集中在城乡和谐发展的途径方面,却忽视了对城乡和谐衡量标准的研究.本文从公平与效率统一(均衡)的视角来解析城乡和谐的标准以及城乡和谐演进的机制,并构建了一个基于公平与效率均衡的城乡和谐发展模型.该模型揭示,城乡和谐是公平与效率均衡的函数,市场机制与政府制度的相互配合共同促进城乡和谐发展.